The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 2009
Filed:
Sep. 09, 2005
Yoshikazu Sato, Gunma, JP;
Mitsuo Sekiguchi, Gunma, JP;
Hiroya Kakimoto, Gunma, JP;
Fuyuki Miyazawa, Gunma, JP;
Tetsuharu Kubo, Gunma, JP;
Yoshikazu Sato, Gunma, JP;
Mitsuo Sekiguchi, Gunma, JP;
Hiroya Kakimoto, Gunma, JP;
Fuyuki Miyazawa, Gunma, JP;
Tetsuharu Kubo, Gunma, JP;
Taiyo Yuden Co., Ltd., Tokyo, JP;
Abstract
The invention provides a method effective in detecting a reproduction signal in real time correction in which correction is simultaneously performed with recording. In this method, a laser beam emitted from a laser diodeis divided into a plurality of beam spots by a diffraction grating. One of the plurality of beam spots is used as a beam spot for recording, and another beam spot is used as a beam spot for reproduction. Reflected light components obtained from these beam spots are independently detected by a detector. A period for which a recording laser beam is in an ON state is referred to as a gate signal, and a mask is put on an RF signal obtained from a beam spot for reproduction, thereby selectively detecting pits reproduced when the recording laser beam is in the ON state.